Multiple forms of TRPC2 mRNA were characterized clarifying differences among laboratories. The intron-exon structure of the TRP superfamily of cation channels summarized in a review. The recombinant TRPC3 expressed in HEK cells was evaluated for its sensitivity to activation by IP3 receptor and found not to be affected. This opens the question as to what previous data showing TRP-interacting peptides of the IP3 receptor affect capacitative calcium entry. Further delineation of this recently discovered class of cation channels is proposed to be obtained from studying mice with targetted disruption of the relevant genes. Two already exist.